1. Field of Invention
The invention relates to an image forming apparatus having a device for removing foreign matter adhered onto a photosensitive member.
2. Description of Related Art
In an image forming apparatus such as a laser printer or a copying device, a cleaning device of a cleanerless type has been known. In the cleaning device of the cleanerless type, toner that is not transferred onto paper and remains on the photosensitive drum is returned to a developer. Therefore, the cleaning device of the cleanerless type does not require a cleaning device for cleaning the photosensitive drum such as a cleaning blade or a storing device for storing toner that is removed.
In the cleaning device of the cleanerless type, the toner remaining on the photosensitive drum is collected temporally by a cleaning roller, and the collected toner is discharged onto the photosensitive drum and collected by the developer when an image forming operation is not carried out. The cleaning roller is formed of a conductive elastic member and arranged so as to be rotated and in contact with the photosensitive drum. By applying an electric potential difference between the cleaning roller and the photosensitive drum, the remaining toner on the photosensitive drum is electrically attracted and collected when the image forming operation is carried out, and the electric potential difference between the cleaning roller and the photosensitive drum is reversed and the collected toner is discharged onto the photosensitive drum when the image forming operation is not carried out.
The invention is directed to an image forming apparatus having a device for removing foreign matter adhered onto a photosensitive member. The image forming apparatus according to a first exemplary aspect includes a photosensitive member that holds an image formed by a developing agent, a charging device that charges a surface of the photosensitive member, a voltage applying device that applies a voltage to the charging device, a first cleaning element that contacts the surface of the photosensitive member, a second cleaning element that contacts a surface of the first cleaning member, and a first voltage controlling device, connected to the charging device, the first cleaning element and the second cleaning element, that generates a predetermined potential difference between the first cleaning element and the second cleaning element based on the voltage applied to the charging device.
The image forming apparatus according to a second exemplary aspect includes a photosensitive member that holds an image formed by a developing agent, a charging device that charges a surface of the photosensitive member, a voltage applying device that applies a first voltage to the charging device, a first cleaning element provided at the surface of the photosensitive member, a first voltage controlling device, connected to the charging device and the first cleaning element, that applies a second voltage to the first cleaning element based on the first voltage applied to the charging device, and a second voltage controlling device, connected to the charging device and the photosensitive member, that applies a third voltage to the photosensitive member based on the first voltage applied to the charging device such that a potential difference is generated between the photosensitive member and the first cleaning element.